Window 7: Coordination – TBI, Concussion, Sports PerformanceWritten By: David Burns
Motor coordination is a great window into cerebellar function and the various tests also serve to breakdown the region into midline, intermediate and lateral related issues. If you recall from the glossary of terms, there was mention of how various areas can be broken down into midline, intermediate and lateral. There are other terms for this division but it is not important for the sake of this blog and is likely not interesting to most readers. Suffice it to say when looking at cerebellar functions (as well as other areas), a functional neurology exam takes into account what specific area, nuclei or functional region may have questionable functional output.
Finger to nose test is a very common test. When examining this function I am looking at several things. First off, I am looking at symmetry of function as always. I look to see the smoothness of the movement throughout all phases of the action. I note differences in the accuracy and quality of the landing on the tip of the nose. There is something significant about a tremor, stopping short of the nose or squashing the nose.
Next I look at rapid alternating movements and this is done in a couple of positions. That is with the arms extended and with the arms in at the side. The latter offers stabilization of the shoulders and therefore change in performance between the two can suggest a brain based vs. cerebellar based issue. As always, I am comparing the quality of function of one side vs. the other. In addition, looking for differences between when one side is performed on its own vs. both sides together. Bilateral motor function is related to specific frontal cortex areas.
These rapid alternating movements are assessed for the speed, accuracy, coordination and symmetry of the movements. Other movements that are evaluated include repetitive tapping movements, complicated hand or foot movements (e.g. figure eight) and motor sequencing challenges like “rock, knife, paper” or rapid thumb finger tapping.
The most midline aspects of cerebellum and brainstem are concerned with spine stabilization, and eye coordination and movement. The intermediate areas are concerned more with proximal joint function (shoulders and hips) and the lateral structures relate to distal structures like the hands and feet. This middle to lateral reference holds true for the deep cerebellar nuclei and their function is partly evaluated based off of these examination findings.
Often times the cerebellum, as part of this system for coordination, is thought of as important only for balance. This is far from the truth. The cerebellum is related to the initiation of all activity other than eye movement. With respect to eye movement however it coordinates and influences things like visual tracking. Whether or not you are talking about the smoothness of the finger to the nose test or the smoothness of eye tracking or smoothness of thought process the cerebellum may very well be the area of deficit when problems arise.
This blog and the other blog “windows” into brain function are not intended for anybody to make any diagnosis or determine treatment for anybody. It is simply intended to help patients understand what a functional approach to neurology, brain function, concussion management, sports performance evaluation may entail. But most importantly, to help the patient or client communicate with the provider so that they or their children can achieve the best brain health possible. Achieving optimal brain health is an interdependent process, an active process that starts with communication.